i think around the mediterranean sea the Israeli´s have the most elaborate technics to save and distribute rare water and to produce it by seawater dissalting.
Whether it is possible to transfer this technics to other regions, this depends on at least three main factors:
- knowledge: the presence of people who are competent to implement these technics,
- capital: for to invest into the wages of this people and into the technical hardware,
- security and stability: the lack of these factors is the main obstacle to invest capital and knowledge into a specific region.
Corruption and war are destroying historic irrigation technics (f.e. canals and viaducts) and traditional local knowledge about the management of rare water ressources who kept regions alive for some thousands of years.
Without stopping corruption and war and without reconstructing/implementing institutions(*) which will guarantee the retourn of investments into common goods and their fair distribution, even the most elaborated irrigation technic will be useless.
(*edit: for implementing institutions see the work of Elinor Ostrom: "Governing the Commons", today supported by this "commons movement strategy center":http://www.onthecommons.org/magazine/el ... g-commmons
There is a second aspect:
the export of "virtual water" in form of water-intensive products from dry regions to wealthy regions.
In most dry regions the water would be enough for the self-reliance of a fitting population-number with a region-specific lifestyle.
But todays economic structures motivate a capital-strong elite to occupy land and water-ressources for to produce water-intensive crops for export.
They let their traditional working neighbours fell dry and at last chase them from their land.
So is the mad situation that in our well-rained green landscapes of middle Europe the children of Farmers have to leave their farms, earning their money in a buerocratic job, consuming products which are produced by water-ressource and slave exploitation in dry regions.
It needs a reformation for earning money by solar-powered administration jobs in well-climatisied offices in hot dry regions, consuming food from the green areas.
But the most important aspect before all the others is to stop or at least minimalise climate change!
Without this all the other efforts will be obsolete!
Obviously, the capitalistic market economy is too short-minded to set the right impulses for that transformation.
So it is the challenge for the civil society of the world to create rules and nudges for a sustainable economy.